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Occupational asthma
Occupational asthma is caused by an agent at work – usually sensitisation to a substance after a latency period, sometimes irritation from an acute high exposure – and the most effective treatment is early, complete removal from the sensitising agent.
Why it matters in the exam
It is the most common occupational lung disease in developed countries, and about 16% of adult-onset asthma is work-related. Questions present a baker, a hairdresser, a car spray painter or a laboratory animal worker with breathlessness that improves on holiday, and ask for the right work-up (serial peak flow recording) and the recommendation (complete removal, not just a mask). They also test the difference between sensitiser-induced asthma, acute irritant-induced asthma (RADS) and pre-existing asthma aggravated at work, and the classic agents of each type. Work-related rhinitis and conjunctivitis often come first and are an early clue.
Key points
- Occupational asthma is the most common occupational lung disease.
- Serial peak flow recording at work and at rest is the core test; the specific inhalation challenge is the gold standard.
- High molecular weight agents (flour, latex) act through IgE; isocyanates usually do not.
- RADS: a single high exposure, symptoms within 24 hours, no latency.
- In sensitiser asthma, complete early removal is the most effective treatment.
Summary table
| Type | Mechanism and latency | Typical agents | Main treatment |
|---|---|---|---|
| Sensitiser asthma, high molecular weight | IgE, latency of months to years | Flour and enzymes, latex, laboratory animal proteins | Complete, early removal |
| Sensitiser asthma, low molecular weight | Usually not IgE-dependent, variable latency | Isocyanates, anhydrides, hairdressing persulfates, western red cedar | Complete, early removal |
| Acute irritant asthma (RADS) | No latency, symptoms within 24 hours of a single high exposure | Chlorine, ammonia, fumes in an accident | Treat as asthma, return possible with controls |
| Work-exacerbated asthma | Pre-existing asthma worsened by irritants | Dust, cold, fumes, exertion | Optimise treatment and improve conditions |
| Irritant asthma from repeated exposure | Repeated moderate irritant exposure | Cleaning and disinfecting agents | Reduce exposure and treat |
A free exam question
:על פי המאמר weight sensitizing agents ‐ molecular ‐ and low ‐ Are high associated with different clinical phenotypes of occupational asthma? מה אופייני יותר לאסטמה תעסוקתית, הנגרמת על ידי חשיפה לנדפי ריתוך, מאשר לאסטמה תעסוקתית הנגרמת מחשיפה ל אבק ?דגנים (the question as examined, in Hebrew)
- א. ריניטיס, דלקת לחמית העין ופגיעה בתפקודי הריאות הבסיסיים
- ב. תגובה לטנטית ארוכה יותר עד להתפתחות האסטמה, תגובה אסטמתית מאוחרת והתלקחויות חמורות יותר
- ג. תחושת לחץ בחזה בעבודה ,חו כי מדי יום ,תגובה ת אס ית טמ מאוחרת והתלקחויות חמורות יותר
- ד. אסטמה המוגדרת כחמורה יותר, על פי הקריטריונים של ה- American Thoracic Society
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: Occupational medicine, Medical licensing exam (IMLE), Internal medicine, Family medicine.
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Sources
- GINA, Global Strategy for Asthma Management and Prevention, 2024 — Occupational asthma
- ERS Task Force, Management of work-related asthma, 2012 — Diagnosis and management of occupational asthma
- LaDou & Harrison, CURRENT Diagnosis & Treatment: Occupational & Environmental Medicine, 6th ed., 2021 — Occupational lung diseases
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.